关键词: 放牧, 青藏高原, 高寒草地, 微生物生物量

Abstract: Soil carbon and nitrogen are the primary nutrient sources of plant growth,playing a crucial role in maintaining soil fertility,enhancing soil microbial activity,and mitigating global climate change. This study used the Qinghai Provincial Alpine Grassland-Livestock Management Technology Platform （https：//ghcd.agiot.cn） to investigates the impacts of different grazing patterns on various carbon and nitrogen components. The results showed that grazing yak and Tibetan sheep separately significantly increased microbial biomass carbon,whereas mixed grazing significantly decreased it. In terms of microbial biomass nitrogen,both separate and mixed grazing significantly reduced its content. Grazing had no significant effect on soil total carbon and soil total nitrogen. The influences of grazing on microbial biomass carbon,microbial biomass nitrogen,soluble organic carbon,and soluble organic nitrogen were more pronounced than that on soil total carbon and soil total nitrogen. From the perspective of microbial biomass,mixed grazing was preferable in alpine grasslands,as separate grazing exacerbated soil microbial carbon limitation in these ecosystems. This study quantified the carbon and nitrogen content of different soil components in alpine grasslands under various grazing patterns,providing a scientific basis for sustainable grassland management in this region.

Key words: Grazing, Qinghai-Xizang Plateau, Alpine grassland, Microbial biomass